"Forward propulsion in freestyle swimming is predominantly achieved through arm action. Few studies have assessed the effects of arm training on arm power and swimming performance, yet there have not been any investigations on the effects of arms-only swimming training on swimming performance and physiological responses to arm exercise."

This study investigated the changes in arms-only and full-stroke swimming performance, movement economy, and aerobic power after an arms-only swimming training program. Male county level swimmers (N = 15) were assigned either to an experimental (N = 8) or control group (N = 7). For six weeks the experimental group performed arms-only freestyle swimming exercises for 20% of their weekly training distance three times per week, whereas the control group performed their usual swimming training. Before and after the training program, both groups performed a) two time trials, 186 m using arms-only and 372 m using full-stroke freestyle swimming, and b) an incremental arm-pulling exercise test. The time to complete the trials was recorded. Peak oxygen uptake (VO2peak), peak exercise intensity, submaximal oxygen uptake at 60 W, and exercise intensity at ventilatory threshold were determined from the exercise test.

After training, the experimental group had improved in arms-only swimming, submaximal oxygen uptake at 60 W, peak exercise intensity, and exercise intensity at ventilatory threshold, but not in VO2peak or in the 372 m using full-stroke swimming. None of the measures changed in the control group.

Implication. Arms-only swimming training at 20% of the weekly training distance improved arm conditioning and performance in arms-only swimming. However, there was no transfer of that specific training effect to free swimming. Arms-only training improves only arms-only swimming and some physiological measures associated with that effect.